The Study of Nonparametric Estimate Method for Left Truncated and Right Censored Data / 中国卫生统计

Objective Nonparametric maximum likelihood estimate(NPMLE)and Breslow-Fleming-Harrington estimate(BFH)are extremely sensitive to small risk set for left truncated and right censored data,this study aims to develop estimation methods to improve the estimation accuracy and compare the existing methods.Methods We introduced the NPMLE,weighted NPMLE,conditional NPMLE,BFH and a new weighted BFH estimate.Simulation studies were carried out to compare five methods via the integrated absolute error(IAE) and integrated average width(IAW).Results The IAE of NPMLE,BFH,weighted NPMLE,weighted BFH and conditional NPMLE is ascending in turn;The IAW of weighted BFH is the lowest and NPMLE is the largest,BFH,conditional NPMLE and weighted NPMLE is reversed under different censored rate.Conclusion According to the results of simulation and example,weighted BFH and weighted NPMLE is recommended in turn when the risk set is small.Otherwise,the results of five methods would be consistent.

History of Spinal Deformity Surgery Part I: The Pre-modern Era

Spinal deformity is one of the oldest known diseases that date back thousands of years in human history. It appears in fairy tales and mythologies in association with evil as its dramatic appearance in patients suffering from the disease easily lent itself to be thought of as a form of divine retribution. The history of spinal deformity dates back to prehistoric times. The early attempts to treat patients suffering from this disease started from Hippocrates age. Side traction or axial traction and cast immobilization were the only possible option prior to the discovery of anesthesia. The first surgical attempts to correct scoliosis occurred in the mid 19th century with percutaneous myotomies of the vertebral musculature followed by postoperative bracing, which outcomes were very quite horrifying. Hibbs' fusion operation had become a realistic treatment option to halt the progression of deformity in the early 20th century. Harrington's introduction of the internal fixation device to treat paralytic scoliosis in 1960's started revolution on deformity correction surgery. Luque developed a segmental spinal using sublaminar wiring technique in 1976 and Cotrel developed Cotrel-Dubousset (CD) instrumentation, which was a posterior segmental instrumentation system that used pedicle and laminar hooks on either thoracic or lumbar spine and pedicle screws on the lumbar spine.

Modified Harrington Procedure for Acetabular Insuficiency Due to Metastatic Malignant Disease

Extensive peri acetabular osteolysis caused by malignant disease process is a major surgical challenge as conventional hip arthroplasty is not adequate. We describe a modified use of the Harrington procedure for acetabular insufficiency secondary to metastatic disease in twelve patients. The procedures include application of multiple threaded pins to bridge the acetabular columns, anti protrusio cage and cemented acetabular cup. Eleven patients were able to walk pain free and achieved a mean Musculoskeletal Tumour Society Functional Score of 80 (range, 68 to 86).

Harrington Instrumentation with Sublaminar Wiring for the Fracutures and Dislocations of Thoracic and Lumbar Spine / 대한정형외과학회잡지

For the evaluation of the clinical and radiologicaI result in the surgical reduction and internal stabilization of the fracture-dislocations in the thoracic and lumbar area, the authors analysed the 39 patients who were treated with Harrington instrumentation supplemented by segmental sublaminar wiring and were follow up 24 months in average. l. Indications for the operation were: compression type with more than 50% of body wedging, bursting type with less than 30% of canal involvement without cord injury, fracture-dislocation type with instability and any type with complete cord injury. 2. Amount of fusion were 6 segments in 25 cases, 7 segments in 11 cases, 5, 8 and 10 segments in 1 case each. 3. Among 31 cases whose lumbar segment were involved in fusion, numbers of movable lumbar motion segments were three or less in 26 and two or less in 8. 4. Angular deformity were changed from 27 preoperatively to 8 postoperatively and to 12 at the end of follow up. Wedging amount of anterior vertebral height were 53% preoperatively, 23% postoperatively and 27% at the end of follow up. 5. External support were applied for 4 months in 35 cases; Taylor brace in 22, TLSO in 10 and body cast in 3. Ambulation was started within a week according to the general status. 6. Solid bony union were observed in 38 cases within 4 months period. Dislodgement of instrumentation and deep infection in one each patient were observed as operative complications. 7. Among 21 cases with cord injury symptoms, 18 cases with complete type showed no neurological recovery, but 3 cases with incomplete type showed complete recovery. It is concluded that the Harrington instrumentation with sublaminar wiring is an effective method of reduction and stabilization for the fracture and dislocations of the thoracic and lumbar spine. On the other hand, the operation is an extensive procedure with significant involvement of lumbar motion segments.

Treatment of Unstable thoracic and Lumbar Spine Fracture with Harrington Segmental Spinal Instrumentation (SSI) / 대한정형외과학회잡지

This is a retrospective clinical and roentgenographic study to measure the correction of deformity and rigidity of Harrington SSI in the stabilization of unstable thoracic and lumbar spine fractures. 35 patients with unstable thoracic and lumbar spine fracture were treated with Harrington SSI from Feb. 1985 to Mar. 1987 in SNUH and 29 patients were followed up for more than 1 year, average 15.6 months. At final follow up of these 29 patients, 73.1% of patients gained neurologic improvement. Measurement of correction of anterior, middle and posterior column height, local kyphosis and anteroposterior offset were 29.7%, 5.2%, 31.2%, 12.8°and 5.3mm and loss of correction of these were 6.5%, 0.1%, 5.8%, 3.1°and 1.1 mm.

Clinical Aspect of Fixation with Harrington Rods of Unstable Thoraco . Lumbar Spine Fracture and Fracture-Dislocation

From January, 1984 to January, 1985 twelve patients with unstable fracture and fracture-dislocation of the thoraco . lumbar spine with neurologic deficits were treated with Harrington Instrument. Fixation by Harrington Instrumentation appeared to provide stabilization, reduction and return of neural function. Author performed Harrington Instrumentation with experience of 12 cases of unstable thoraco . lumbar spine fructure and fracture-dislocation with neurologic deficits. Results were as follows : 1) Spinal fracture and fracture-dislocation were most common in thoraco . lumbar Junction. 2) Harrington Instrumentation was very effective for keeping the spine stability in unstable fracture. 3) Six cases (50%) had a complete neurologic deficit and six cases (50%) had a incomplete neurologic deficit, two cases of the six patients with complete neurologic deficits recovered slightly but two cases with incomplete neurological deficit gained complete recovery. 4) During the postoperative period, early ambulation was possible and average admission period were 71 days. 5) Correction of spinal deformity. A. Average value of kyphotic angle (12.5 degrees). B. Average value of Iw(Index of weding) (1.32). C. Displacement was completely corrected in eight patients (100%).

Operative Treatment of Dorsolumbar Fractures and Fracture Dilocations: Clinical Experiences / 대한정형외과학회잡지

Since the introduction of Holdsworth's new classification on fracture-dislocations of spine with particular emphasis on the role of posterior ligmaent complex, operative reduction and spinal fusion is considered to be an established procedure in treating unstable injuries of the thoracolumbar spine.By stabilizing unstable fractures,nursing, and rehabilitation become much easier. Among the various methods and devices, Harrington instrumentation and posterior spinal fusion have been used and found to be acceptable in our series. Twenty five consecutive patients with unstable fractures and fracture-dislocations' of thoracolumbar spine were treated by open reduction and spinal fusion with Harrington rod fixation at the Department of Orthopedic Surgery, Kang Nam General Hospital Public Corporation from the period of 1982 to 1985. The following results were obtained from analysis of the cases. l. Among 25 cases, 15 (60%) were due to flexion-rotation violence, 5 pure flexion,3 vertical compression, 1 shear fracture respectively. 2. Among 16 cases with neurologic deficit, 15 cases showed considerabel improvement after surgery. 3. Most of the cases showed satisfactory bony fusion, and average postoperative kyphotic angle was 14.4 after 3 months. 4. Although no particular external fixation was adopted, permitting mobility in bed, postoperative correction was relatively well maintained.

Harrington Distraction Rods without Fusion for Thoraco-Lumbar Fracture or Fracture-Dislocation / 대한정형외과학회잡지

Management of patients with unstable fracture or fracture-dislocation of thoraco-lumbar spine continues to be controversial. One area of disagreement involves spinal fusion with internal fixation for prevention of later spinal instability. Intemal fixation of the spine without fusion has been advocated in the treatment of the unstable thoraco-lumbar fracture or dislocation. During the period of January 1981 to March 1984, thirty-two patients underwent fixation by Harrington distraction rod without fusion for the treatment of thoraco-lumbar fractures. Eight cases among them had second operation for the removal of the Harrington rods in 13.4months after Harrington rod fixation and were followed up clinically and radiolagically for 1 year at the Department of Orthopaedic Surgery, St. Mary's Hospital, Catholic Medical College and Center. The rationales for this procedure were to minimize the number of permanently stabilized segments and to provide more spinal mobility. We have expected that spontaneous fusion of vertebral body occur by the prolonged immobilization with Hamngton distraction rods. After the Harrington rods, the average conection rate of kyphotic angle was 41.8% and average correction rate of height of collapsed vertebral body or displacement of vertebral body was 42.3% at one year follow up. Instrumentations in eight patient were removed at 13.4 months after the initial surgery and the patients were followed up for one year. At the time of removal of instrumentation, unilateral partial facetectomy was done for histologic examination of the facet joint which is above the lower Harrington hook in four patients. The average correction rate of kyphotic angle was 37.5% and the average correction rate of height of collapsed or displaced vertebral body was 40.6% at one year after the removal of H-rods. The range of spine motions were incresed gradually. But histologic findings of the immobilized facet joint revealed fibrillation, fissures, thinning of the normal cartilagenous surface, decreased cartilagenous cellularity, and vascular tidemark invasion which are characteristics of osteoarthritis. Through this study, we obtained following conclusions: 1. Immediate Harrington distraction rodding was effective for the anatomic reduction of the collapsed vertebral body. And it provided immediate spinal stability, and spontaneous fusion of vertebral body. 2. Prolonged immobilization of the spine by Harrington rods is believed to have deleterious effect on articular cartilage of the immobilized facet joint as the degenerative changes of the cartilage of the facet joint was consistently found in this study. And it was regarded as a predisposing factors in the development of symptomatic arthritis of the spine. 3. If a fractured and collapsed vertebral body can be reduced by Harrington distraction rods, a spontaneous fusion of vertebral body occur. Harrington rodding without fusion could be one of the useful surgeries for management of the fractures and fracture-dislocation of the spine.

Segmental Spinal Instrumentation in the Management of Fracture and Fracture-Dislocation of the Thoraco-Lumbar Spine / 대한정형외과학회잡지

Segmental Spinal Instrumentation(S.S.I.) is more effective means of managing unstable thoraco-lumbar spine fractures than traditional Harrington Rod Instrumentation as an operative procedure which afforded rigid internal fixation with stability and needed minimal external immobilization. Early return to normal activity and successful rehabilitation are facilitated by efficient stabilization with S.S.I. Fifty-nine patients with fractures and fracture-dislocations of thoraco-lumbar spine were treated by Harrington Rod Instrumentation (29 patients) and S.S.I. (30 patients) at this hospital from June 1979 to July 1984. We have analysed the results of these treatment and obtained following conclusions: 1. S.S.I. is more rigid internal fixation than Harrington Rod Instrumentation. a) no or minimal external immobilization b) early ambulation and rehabilitation c) lowered complications 2. There was no significant difference in correction rate, loss of correction, and neurologic recovery between Harrington Rod Instrumentation and S.S.I.

Harrington Rod Stabilization of Thoracic and Lumbar Fractures in Neurosurgery(Clinical Study)

Harrington Instrumentation to treat the unstable fracture (including the fracture dislocation) of the thraco-lumbar spine with neurologic deficits is a very effective method. This method provides rigid fixation and stability for thoracolumbar fracture, also offers the optimum condition for recovery of nerve roots, and decompresses the spinal canal with anatomical reduction. The principal advantage for this method of treatment is the early mobilization of the patient and enhanced rehabilitation. Authors, performed Harrington Instrumentation with a laminectomy experienced 20 cases of unstable thoraco-lumbar spine fracture(including the fracture-dislocation) with neurologic deficit from Aug. 1980 to Oct. 1984. The following results were obtained : 1) Of twenty patients, the patients at the age 20 to 49 were commonly injured and predominant cause of spinal injury was falling accident. 2) The thoraco-lumber fracure(including fracture-dislocation) were thoracolumbar junction, the commonest site among them was the lst lumber vertebra, and the commonest mechanism of spinal injury way flexon injury. 3) Most commonly, paraplegia was with twelve thoracic vertebra injury, and paraparesis was with lst lumbar vertebra. 4) Correction of the kyphotic deformity was 8 degree on the average, and the range of the correction was between 0 degree and 19 degree. 5) Neurological recoveries were gained from 14 patients(70%), and the 10 patients(50%) among them were completely recovered. 6) Average hospital periods were 78 days and after an average 21 postoperative days, ambulation was started. 7) In complication, three hook dislocations were occured. 8) Early operation (laminectomy for posterior decompression and Harrington Instrumentation for anterior decompression) was very effective in spinal cord injury.

Management of Unstable Thoraco / 대한정형외과학회잡지

Segmental wiring to treat the unstable fracture and fracture-dislocation of the thoraco-lumbar spine is more effective method than Harrington instrumentation as primary procedure which afforded immediate rigid internal fixation of the spine and permitted mobilization without external support and immediate rehabilitation. A clinical study was made of twenty seven patients who were hospitalized and treated at the Department of Orthopaedic Surgery, Wonju Christian Hospital from Feb. 1979 to Apr. 1983. The following results were obtained: l. Of twenty seven patients, nine(33.3%) had a flexion rotation, eight(29.6%) had a shearing, eight (29. 6%) had a flexion compression and two(7.5%) had a vertical compression by Holdsworths mechanism of injury and by Pauls classification of fracture, thirteen(48. 1%) had a flexion distraction fracture, twelve(44. 4%) had a translation fracture and two(7. 5%,) had a unstable burst fracture. 2. Fifteen(55. 6%) had a complete neural deficit and five(18. 5%,) had an incomplete neural deficit. Six(22.2%) of the fifteen patients with complete neural deficit and one(3. 7%.) of the five patients with incomplete neural deficit showed slight neurological recovery, but eight(29.6%) gained complete recovery. 3. Correction of kyphotic deformity was average 12. 4 degree in Harrington instrumentation and average 18. 0 degree in segmental wiring, and during the follow-up periods, there was a final loss of 6. 3 degrees of kyphotic correction in Harrington instrumentation and 3. 0 degrees in segmental wiring. 4. In external support, fourteen(51.9%) had body jacket cast and four(14.8%) had back brace in Harrington instrumentation, but all patients except one brace had no external support in segmental wiring. 5. In complication, two hook dislocations and two pseudoarthroses were occurred in Harrington instrumentation, but any complication except only one cases of wound infection was not occurred in segmental wiring.

A Clinical Study of the Surgical Treatment of the Thoraco-Lumbar Spinal Injuries / 대한정형외과학회잡지

Among 334 thoracolumbar spinal injury patients who were admitted to this hospital from June 1972 to June, 1982, 66 patients with fracture and fracture dislocation of thoraco-lumbar spine which were defined as unstable clinically and radiologically were treated with surgical measures. The ratio between male and female was 7.3:1, the majority was found in third and fourth decade (46 cases, 69%), and the most common cause of injury was falling from a height (38 cases, 58%). The most common site of the injury was lumbar spine (29 cases, 44%) and the most common mechanism of injury was flexion-rotation (29 cases, 44%). Our surgical measures were Harrington rod instrumentation with either anterior or posterior fusion (25 cases, 38%), posterior wiring and fusion (14 cases, 21%), anterior decompression and anterior fusion (14 cases, 21%), posterior fusion (4 cases, 6%), anterior fusion and posterior fusion (3 cases, 5%) and etc. The average correction of displacement was 65% and the average correction of kyphotic deformity was 50%. The most remarkable correction was found at the cases of Harrington rod instrumentation (71%, 74%). Neurological deficit had already developed in 43 cases(65%) prior to operation, and the recovery was observed in 18 cases(42%). Most excellent recovery of neural deficit was found also at the cases of Harrington rod instrumentation (11 cases, 52%). We have analysed the results of these treatment and obtained following conclusions. 1. For the unstable fracture and fracture-dislocation of thoraco-lumbar spine with or without neural involvement, immediate surgical treatments were valuable to expect restoration of anatomical reduction and promotion of every possible recovery of neural function with spinal stability and fewest complication. 2. Fixation with Harrington rod instrumentation appears to provide better reduction and stability with neural improvement than other methods, and therefore early undertaking of rehabilitation activities is possible. 3. For the patients who are seriously compromised or require anterior decompression, immediate posterior reduction and fixation with Harrington rod instrumentation followed anterior decompression and anterior fusion of the involved segments at the eariest feasible time, we feel, is the treatment of choice.

Scoliosis in Neurofibromatosis / 대한정형외과학회잡지

Neurofibromatosis is a disease which involves both neuroectodermal and mesodermal tissue, and is characterized by cafe-au-lait spot, multiple subcutaneous neurofibromas, elephantiasis neuromatosa, a positive family history, and specific dystrophic osseous changes such as scoliosis, penciling of ribs, vertebral scalloping, a paravertebral soft tissue tumor, and congenital pseudarthrosis. The classic type of scoliosis in neurofibromatosis was known as a sharp localized short curve that is often rapidly progressive and produces severe deformity with dystrophic changes, but another form with long gentle curve is reported. Since conservative treatment is usually unsuccessful, posterior fusion with or without Harrington instrumentation is the treatment of choice even in young age when the curve is progressive. This paper was aimed to review our experience with 11 patients having neurofibromatosis and scoliosis, who were treated with posterior fusion and Harrington instrumentation from Jan. 1971 to Dec. 1980, and the results were as follows: 1. The average age that spinal deformity was observed was 7.7 years old, but the average age at treatment was 14.4. 2. Cafe-au-lait spot was observed in all cases, subcutaneous nodule in 7 cases, local gigantism in 2 cases, and positive family history in 3 cases. 2 cases were combined with congenital spinal anormalies. 3. Specific pattern in spinal deformity was not significant. There were 7 short curves less than 5 vertebrae involved and 6 long curves more than 6 vertebrae involved. 4. There were 5 kyphosis which had more than 50°, and those were usually combined with severe scoliosis. 5. Preoperative average degree of scoliosis was 93.8, and the final correction was 41.2° (43.9%) with loss of correction 5.3°(5.7%) after 3.2 year follow-up in average. 6. It shouid be educated for early detection at home and school, and for the importance of early treatment for the scoliosis, to prevent rapid increase of scoliosis in neurofibromatosis.

Fixation with Harrington Rods of Unstable Thorace-Lumbar Spine Fracture and Fracture-Dislocation / 대한정형외과학회잡지

Harrington Instrumentation and Spinal Fusion to treat the unstable fracture and fracture-dislocation of the thoraco-Iumbar spine is a very effective method. This method not only decompresses the spinal cord and nerve roots by anatomical reduction and preserves spinal stability, but also makes possible early rehabilitation and prevention of complications. A clinical study was made of twelve patients who were hospitalized and treated at the Department of Orthopaedic Surgery, Chung-Nam National University Hospital from Oct. 1978 to J une 1980. The following results were obtained: 1. Of twelve patients, five(42%) had a flexion-compression fracture, four(33.3%) had a shear fracture-dislocation, two(16.7%) had a flexion-rotational fracture, and one(8.3%) had a bursting fracture. 2. Seven(58%) had a complete neural deficit and five (42%) had an Incomplete neural deficit. Two (28%) of the seven patients with complete neural deficit showed slight neurological recovery, but two patients(40%) with incomplete neural deficit gained complete recovery. 3. Correction of the kyphotic deformity was 16 degrees on the average, and the displacement was completely corrected in five of the six patients. 4. During the follow-up period, there was a final loss of about five degrees (range 3-16 degree) of kyphotic correction In our patients and there was no difference in loas of correction between laminectomy group and control group. 5. After an average of 18 postoperative days, ambulation was started, and acute hospital days were 77 days on the average. 6. There was no difference in spinal fusion rate between brace-wearing group (4 cases) and cast Immobilized group (8 cases). 7. Two cases (16.6%) of the twelve cases showed spontaneous interbody fusion.